BRYN MAWR, Pa.- When Sharhea Wade arrived at Bryn Mawr College from a big-city high school, it seemed as if every other student on the quiet, leafy campus had graduated from an exclusive private school.

"I felt intimidated by them," recalled Wade. "Bryn Mawr is a different world."

Yet whenever she felt like a fish out of water, Wade could turn to her "posse" - nine other girls who, like her, had been recruited from struggling Boston-area school districts and sent on full-merit scholarship to the elite women's college.

Wade's posse is one of dozens sent to top-tier universities each year by the New York-based Posse Foundation. The combination of monetary and social support is a model experts say could help move the U.S. toward President Barack Obama's goal of having America lead the world in the percentage of college graduates by 2020. Next fall, the program hits the Ivy League when it debuts at the University of Pennsylvania.

So far, Obama's focus has been on increasing access to higher education - especially for minority and low-income students- through expanded Pell Grants and simplified financial aid applications.

But paying for college is only part of the battle. Keeping students in school by supporting their psychological and academic needs is equally important, said Dr. Laura Perna, an associate professor in the University of Pennsylvania's Graduate School of Education.

Posse founder Deborah Bial started the organization in 1989 after a once-promising inner-city student told her, "I never would have dropped out of college if I had my posse with me."

Since then, Posse has sent more than 2,600 students to its partner campuses, including Vanderbilt University, Colby College and the University of California at Berkeley.

The program targets students in disadvantaged urban districts who have strong leadership skills but may lack the guidance to wade into what can be an intimidating college admissions process. Posse is not need- or minority-based, though many students fit both categories.